The invention relates to a covering for an opening made in roads, squares, courtyards and floors, formed at a frame and a top cover, cap or grating placed in the frame, on the inside of which is provided a support flange, the top surface of which is constructed as a bearing surface and on which is mounted the cover or grating provided with a marginal contact surface.
The invention relates to means, such as are used in roads, e.g. shaft coverings to cover shafts, drains and sewers. However, such coverings can also be used in squares, courtyards and the floors of buildings, where they serve as coverings for manholes, inspection shafts, etc. Numerous different constructions of such coverings are known and they essentially comprise a frame and a cover or grating inserted in the frame. The frame serves as a border or enclosure for the opening and also as a support frame for the cover or grating. The frame and the cover or grating are preferably laid flush with the ground.
As a function of the place of use, known coverings cause certain problems. In accordance with present tendencies, for saving material and costs, the covers or gratings are manufactured as lightweight constructions. However, they can much more easily be removed, e.g. deliberately or as a result of the traffic flow, or can at least be displaced from their contact surface. It is also difficult to correctly insert the cover or grating, if dirt has penetrated onto the contact surface for the cover and frame.